Outline of MME Lab
Division of Environmental BiosciencesThis division covers a broad range in molecular biological studies of the marine microbial function, antibiotic resistance, fish diseases and food web linkage . The division is comprised of three main research groups: the Marine Molecular Ecology (MME) group, Fish Diseases group and Macro-ecology group. The MME group focuses on marine microbes which play in integral role in the microbial food web, and act as a buffer to ecological stress and chemical pollutants. Studies include advanced research on the microbial loop and molecular ecology of marine microbes. Recent project covers antibiotic resistance and the horizontal gene transfer among various environmental microbes. Results from these studies can be used to develop technology to improve marine industries related to aquaculture and seawater utilization, and monitoring of human and ecosystem health. Our current projects include the following:
1. Biochemistry of dissolved proteins in seawater.
The formation of dissolved organic matter (DOM) is an initial step in the microbial loop. Primary production of DOM by photosynthesis is a "de novo" pathway in DOM production. Also, degradation of biomolecules is another DOM-producing pathway (called the "salvage pathway"). Of the macromolecules, proteins are most important, because they supply a good balance of C and N through the salvage pathway to the microbial loop and primary production. However, the sources and fates of dissolved proteins in the ocean are not clearly understood. What types of dissolved proteins are in seawater? ...We are currently profiling dissolved proteins in seawater using liquid chromatography equipped with tandem mass spectrography. What organisms and mechanisms degrade proteins in seawater? ... To discover this we are examining proteolytic activities in seawater. How do proteins change in seawater? ... We are using membrane proteins of Pseudomonas aeruginosa as model proteins for study of protein degradation. You might ask "why P. aeruginosa proteins?" ....Please see my papers, or e-mail me (S. Suzuki).
References:
1, Thao NV et al (2014) Front. Mar. Sci., 1, article 69, doi:10.3389/fmars.2014.00069
2, Yoshida M et al (2014) J. Oceanogr., 70, 105-113. doi:10.1007/s10872-013-0212-6
3, Bong CW et al (2013) Aquat. Microb. Ecol., 69, 33-46.
4, Wada S and Suzuki S (2011) Aquat. Microb. Ecol., 63, 47.
5, Obayashi Y and Suzuki S (2008) Aquat. Microb. Ecol., 50, 2313.
6, Obayashi Y and Suzuki S (2005) Limnol. Oceanogr., 50, 722.
2. Ecology of resistant bacteria for antibiotics.
Contamination by antibiotics and metals with low concentration in the ocean can affect on microbial ecosystem. Antibiotics themselves are not toxic to human, but the antibiotics can select for drug-resistant bacteria in the environment. Drug resistance genes can further be transferred and spread to various bacterial species, resulting in multi-drug resistant bacteria. Drug resistant bacteria can also be occurred by exposure to various chemicals other than antibiotics. The occurrence of drug-resistant bacteria and dynamics of gene transfer is a newly discovered environmental risk of chemical pollution. We are focusing on the molecular ecology of antibiotic resistance (tetracycline, sulfonamide and quinolone) in marine bacteria, and how the transfer of resistance gene occurs in aquatic environments. Water, sediment and biological samples are all being analyzed. Genetic evolution study of the drug-resistance genes is also included in our project.
References:
1, Suzuki, S. et al (2019) Sci. Total Environ.,699, 649-656.
https://doi.org/10.1016/j.scitotenv.2019.03.111
2, Suzuki S et al (2015) Front. Microbiol., 6, 796, doi: 10.3389/fmicb.2015.00796
3, Pruden A et al (2013) Environ. Health Perspect., 121, 878-885.
http://dx.doi.org/10.1289/ehp.1206446
4, Suzuki S et al (2013) Front. Microbiol., 4, doi:10.3389/fmicb.2013.00102.
5, Suzuki S and Hoa PTP (2012) Front. Microbiol., 3, 67, doi:10.3389/fmicb.2012.00067
6, Suzuki S et al (2012) FEMS Microbiol. Lett., 336, 52-56.
7, Hoa PTP et al (2011) Sci. Total Environ., 409, 2894.
8, Rahman H M et al (2008) Environ. Sci. Technol.,42, 5055.
9, Hoa PTP et al (2008) Sci. Total Environ., 405, 377.
3. Ecology of fish disease viruses.
Opportunistic infection by viruses can cause many problems in humans as well as cultured and wild animals. This project is examining the dynamics of fish pathogenic viruses in marine organisms and the ocean. Currently, this research is focusing on birnaviruses because of their unique properties; they have double stranded RNA as a genome and can infect various kinds of organisms such as fishes and mollusks.
References:
1, Inaba et al (2009) J. Microbiol., 47, 76-84.
2, Inaba et al (2007) Fish. Sci., 73, 615.
3, Zhang CX and Suzuki S (2004) J. Fish Dis., 27, 633.
4, Kitamura SI et al (2004) Dis. Aquat. Org., 58, 21.
5, Zhang CX and Suzuki S. (2003) Arch. Virol., 148, 745.
6, Suzuki S et al (2001) Microbes Environ., 16, 191.
7, Kitamura SI et al (2000) Arch. Virol., 145, 2003.
8, Suzuki S et al (1997) J. Mar. Biotechnol., 5, 205.
